1. Field of the Invention
The present invention generally relates to a heater installed in a fireplace for heating air circulated through the heater and discharging said heated air into a living space or spaces, thereby utilizing heat which is normally discharged up the chimney and rendering the fireplace substantially more effective for heating purposes.
2. Description of the Prior Art
Fireplaces are utilized in present day homes primarily for ornamental purposes and for the satisfaction derived from an open fire rather than for their capability of heating. However, in emergency situations, fireplaces frequently are relied upon for heating purposes. For example, if electrical power is interrupted or if fuel supply to the central heating system becomes depleted, a home owner must frequently rely upon the fireplace for heating purposes even though the inefficiency of a fireplace for heating is well known.
Various efforts have been made to render a fireplace more efficient for heating purposes. Such efforts include permanently installed heat exchange devices with air circulation means incorporated therein which are rather expensive in their initial cost and either must be installed when the fireplace is built or require substantial modification of the fireplace. In addition, efforts have been made to place a heat exchange device in the fireplace and circulate air through it for heating the air. Some devices of this nature combine the heat exchange device with the fuel supporting grate by constructing the grate of tubular pipe and circulating air therethrough. Such devices are not only inefficient heat exchangers but also have a very short useful life in view of the intense heat occurring at the grate especially when live coals are positioned on or under the grate, thus resulting in deterioration and burn-through of the pipes which then permit the air passing through the pipes to pickup sparks and products of combustion and discharge the same into the living space. Examples of heating devices associated with fireplaces in the prior art are found in the following U.S. patents:
1,112,521 October 6, 1914 1,297,964 March 18, 1919 1,783,140 November 25, 1930 2,828,078 March 25, 1958 3,001,521 September 26, 1961 3,240,206 March 15, 1966 3,635,211 January 18, 1972 3,685,506 August 22, 1972.